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Paskal W, Gotowiec M, Stachura A, Kopka M, Włodarski P. VEGF and Other Gene Therapies Improve Flap Survival-A Systematic Review and Meta-Analysis of Preclinical Studies. Int J Mol Sci 2024; 25:2622. [PMID: 38473869 DOI: 10.3390/ijms25052622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Surgical flaps are basic tools in reconstructive surgery. Their use may be limited by ischemia and necrosis. Few therapies address or prevent them. Genetic therapy could improve flap outcomes, but primary studies in this field present conflicting results. This systematic review and meta-analysis aimed to appraise the efficacy of external gene delivery to the flap for its survival in preclinical models. This review was registered with PROSPERO (CRD42022359982). PubMed, Embase, Web of Science, and Scopus were searched to identify studies using animal models reporting flap survival outcomes following any genetic modifications. Random-effects meta-analysis was used to calculate mean differences in flap survival with accompanying 95% CI. The risk of bias was assessed using the SYRCLE tool. Subgroup and sensitivity analyses were performed to ascertain the robustness of primary analyses, and the evidence was assessed using the GRADE approach. The initial search yielded 690 articles; 51 were eventually included, 36 of which with 1576 rats were meta-analyzed. VEGF gene delivery to different flap types significantly improved flap survival area by 15.66% (95% CI 11.80-19.52). Other interventions had smaller or less precise effects: PDGF-13.44% (95% CI 3.53-23.35); VEGF + FGF-8.64% (95% CI 6.94-10.34); HGF-5.61% (95% CI 0.43-10.78); FGF 3.84% (95% CI 1.13-6.55). Despite considerable heterogeneity, moderate risk of bias, and low quality of evidence, the efficacy of VEGF gene therapy remained significant in all sensitivity analyses. Preclinical data indicate that gene therapy is effective for increasing flap survival, but further animal studies are required for successful clinical translation.
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Affiliation(s)
- Wiktor Paskal
- Department of Methodology, Medical University of Warsaw, 1b Banacha Street, 02-091 Warsaw, Poland
| | - Mateusz Gotowiec
- Department of Methodology, Medical University of Warsaw, 1b Banacha Street, 02-091 Warsaw, Poland
| | - Albert Stachura
- Department of Methodology, Medical University of Warsaw, 1b Banacha Street, 02-091 Warsaw, Poland
- Doctoral School, Medical University of Warsaw, 81 Żwirki i Wigury Street, 02-091 Warsaw, Poland
| | - Michał Kopka
- Department of Methodology, Medical University of Warsaw, 1b Banacha Street, 02-091 Warsaw, Poland
- Doctoral School, Medical University of Warsaw, 81 Żwirki i Wigury Street, 02-091 Warsaw, Poland
| | - Paweł Włodarski
- Department of Methodology, Medical University of Warsaw, 1b Banacha Street, 02-091 Warsaw, Poland
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2
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Seyed Jafari SM, Blank F, Ramser HE, Woessner AE, Shafighi M, Geiser T, Quinn KP, Hunger RE, Gazdhar A. Efficacy of Combined in-vivo Electroporation-Mediated Gene Transfer of VEGF, HGF, and IL-10 on Skin Flap Survival, Monitored by Label-Free Optical Imaging: A Feasibility Study. Front Surg 2021; 8:639661. [PMID: 33834037 PMCID: PMC8021947 DOI: 10.3389/fsurg.2021.639661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/22/2021] [Indexed: 12/12/2022] Open
Abstract
Preventing surgical flaps necrosis remains challenging. Laser Doppler imaging and ultrasound can monitor blood flow in flap regions, but they do not directly measure the cellular response to ischemia. The study aimed to investigate the efficacy of synergistic in-vivo electroporation-mediated gene transfer of interleukin 10 (IL-10) with either hepatocyte growth factor (HGF) or vascular endothelial growth factor (VEGF) on the survival of a modified McFarlane flap, and to evaluate the effect of the treatment on cell metabolism, using label-free fluorescence lifetime imaging. Fifteen male Wistar rats (290–320 g) were randomly divided in three groups: group-A (control group) underwent surgery and received no gene transfer. Group-B received electroporation mediated hIL-10 gene delivery 24 h before and VEGF gene delivery 24 h after surgery. Group-C received electroporation mediated hIL-10 gene delivery 24 h before and hHGF gene delivery 24 h after surgery. The animals were assessed clinically and histologically. In addition, label-free fluorescence lifetime imaging was performed on the flap. Synergistic electroporation mediated gene delivery significantly decreased flap necrosis (P = 0.0079) and increased mean vessel density (P = 0.0079) in treatment groups B and C compared to control group-A. NADH fluorescence lifetime analysis indicated an increase in oxidative phosphorylation in the epidermis of the group-B (P = 0.039) relative to controls. These findings suggested synergistic in-vivo electroporation-mediated gene transfer as a promising therapeutic approach to enhance viability and vascularity of skin flap. Furthermore, the study showed that combinational gene therapy promoted an increase in tissue perfusion and a relative increase in oxidative metabolism within the epithelium.
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Affiliation(s)
| | - Fabian Blank
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Department of Pulmonary Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Hallie E Ramser
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, United States
| | - Alan E Woessner
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, United States
| | | | - Thomas Geiser
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Department of Pulmonary Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Kyle P Quinn
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, United States
| | - Robert E Hunger
- Department of Dermatology, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Amiq Gazdhar
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Department of Pulmonary Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
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3
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Khan AA, Paget JT, McLaughlin M, Kyula JN, Wilkinson MJ, Pencavel T, Mansfield D, Roulstone V, Seth R, Halle M, Somaiah N, Boult JKR, Robinson SP, Pandha HS, Vile RG, Melcher AA, Harris PA, Harrington KJ. Genetically modified lentiviruses that preserve microvascular function protect against late radiation damage in normal tissues. Sci Transl Med 2018; 10:eaar2041. [PMID: 29367346 PMCID: PMC6020074 DOI: 10.1126/scitranslmed.aar2041] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 10/15/2017] [Accepted: 11/08/2017] [Indexed: 12/25/2022]
Abstract
Improvements in cancer survival mean that long-term toxicities, which contribute to the morbidity of cancer survivorship, are being increasingly recognized. Late adverse effects (LAEs) in normal tissues after radiotherapy (RT) are characterized by vascular dysfunction and fibrosis causing volume loss and tissue contracture, for example, in the free flaps used for immediate breast reconstruction after mastectomy. We evaluated the efficacy of lentivirally delivered superoxide dismutase 2 (SOD2) overexpression and connective tissue growth factor (CTGF) knockdown by short hairpin RNA in reducing the severity of LAEs in an animal model of free flap LAEs. Vectors were delivered by intra-arterial injection, ex vivo, to target the vascular compartment. LVSOD2 and LVshCTGF monotherapy before irradiation resulted in preservation of flap volume or reduction in skin contracture, respectively. Flaps transduced with combination therapy experienced improvements in both volume loss and skin contracture. Both therapies reduced the fibrotic burden after irradiation. LAEs were associated with impaired vascular perfusion, loss of endothelial permeability, and stromal hypoxia, which were all reversed in the treatment model. Using a tumor recurrence model, we showed that SOD2 overexpression in normal tissues did not compromise the efficacy of RT against tumor cells but appeared to enhance it. LVSOD2 and LVshCTGF combination therapy by targeted, intravascular delivery reduced LAE severities in normal tissues without compromising the efficacy of RT and warrants translational evaluation as a free flap-targeted gene therapy.
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Affiliation(s)
- Aadil A Khan
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
- Department of Plastic Surgery, The Royal Marsden Hospital, London SW3 6JJ, UK
| | - James T Paget
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
- Department of Plastic Surgery, The Royal Marsden Hospital, London SW3 6JJ, UK
| | - Martin McLaughlin
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Joan N Kyula
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Michelle J Wilkinson
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Timothy Pencavel
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - David Mansfield
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Victoria Roulstone
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Rohit Seth
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Martin Halle
- Department of Molecular Medicine and Surgery, Section of Plastic Surgery, Karolinska Institute, Stockholm 17176, Sweden
- Department of Reconstructive Plastic Surgery, Karolinska University Hospital, Stockholm 17176, Sweden
| | - Navita Somaiah
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK
| | - Jessica K R Boult
- Magnetic Resonance Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SM2 5NG, UK
| | - Simon P Robinson
- Magnetic Resonance Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SM2 5NG, UK
| | - Hardev S Pandha
- Postgraduate Medical School, University of Surrey, Guildford GU2 7XH, UK
| | - Richard G Vile
- Molecular Medicine Program, Mayo Clinic, Rochester, MN 55905, USA
| | - Alan A Melcher
- Translational Immunotherapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Paul A Harris
- Department of Plastic Surgery, The Royal Marsden Hospital, London SW3 6JJ, UK
| | - Kevin J Harrington
- Targeted Therapy Team, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London SW3 6JB, UK.
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Basu G, Downey H, Guo S, Israel A, Asmar A, Hargrave B, Heller R. Prevention of distal flap necrosis in a rat random skin flap model by gene electrotransfer delivering VEGF165plasmid. J Gene Med 2014; 16:55-65. [DOI: 10.1002/jgm.2759] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Gaurav Basu
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
| | - Harre Downey
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
| | - Siqi Guo
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
| | - Annelise Israel
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
| | - Anthony Asmar
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
| | - Barbara Hargrave
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
- School of Medical Diagnostics and Translational Science; Old Dominion University; Norfolk VA USA
| | - Richard Heller
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk VA USA
- School of Medical Diagnostics and Translational Science; Old Dominion University; Norfolk VA USA
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Hollenbeck ST, Senghaas A, Komatsu I, Zhang Y, Erdmann D, Klitzman B. Tissue engraftment of hypoxic-preconditioned adipose-derived stem cells improves flap viability. Wound Repair Regen 2012; 20:872-8. [PMID: 23110692 DOI: 10.1111/j.1524-475x.2012.00854.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 07/19/2012] [Indexed: 12/23/2022]
Abstract
Adipose-derived stem cells (ASCs) have the ability to release multiple growth factors in response to hypoxia. In this study, we investigated the potential of ASCs to prevent tissue ischemia. We found conditioned media from hypoxic ASCs had increased levels of vascular endothelial growth factor (VEGF) and enhanced endothelial cell tubule formation. To investigate the effect of injecting rat ASCs into ischemic flaps, 21 Lewis rats were divided into three groups: control, normal oxygen ASCs (10(6) cells), and hypoxic preconditioned ASCs (10(6) cells). At the time of flap elevation, the distal third of the flap was injected with the treatment group. At 7 days post flap elevation, flap viability was significantly improved with injection of hypoxic preconditioned ASCs. Cluster of differentiation-31-positive cells were more abundant along the margins of flaps injected with ASCs. Fluorescent labeled ASCs localized aside blood vessels or throughout the tissue, dependent on oxygen preconditioning status. Next, we evaluated the effect of hypoxic preconditioning on ASC migration and chemotaxis. Hypoxia did not affect ASC migration on scratch assay or chemotaxis to collagen and laminin. Thus, hypoxic preconditioning of injected ASCs improves flap viability likely through the effects of VEGF release. These effects are modest and represent the limitations of cellular and growth factor-induced angiogenesis in the acute setting of ischemia.
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Affiliation(s)
- Scott T Hollenbeck
- Division of Plastic and Reconstructive Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Vural E, Berbée M, Acott A, Blagg R, Fan CY, Hauer-Jensen M. Skin graft take rates, granulation, and epithelialization: dependence on myeloid cell hypoxia-inducible factor 1alpha. ACTA ACUST UNITED AC 2010; 136:720-3. [PMID: 20644069 DOI: 10.1001/archoto.2010.103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To compare the "take" rates of skin grafts between myeloid-selective hypoxia-inducible factor (HIF) 1alpha knockout (KO) and wild-type (WT) mice. Production of the alpha subunit of HIF-1alpha is increased in healing wounds, which stimulates expression of vascular endothelial growth factor (VEGF) to promote angiogenesis. Therefore, the take rate of skin grafts may be closely associated with the presence or absence of HIF-1alpha production in the recipient bed. DESIGN The percentage of healthy graft areas obtained by planimetry and scores for epithelialization and granulation tissue formation obtained by histopathologic analysis were compared in 12 KO and 12 WT mice following skin grafting. RESULTS The graft take rate was significantly impaired in the KO group (P = .009), whereas epithelialization (P = .46) or granulation (P = .41) tissue formation scores did not reveal any significant differences. CONCLUSION Hypoxia-inducible factor 1alpha in myeloid cells may be an important molecule for revascularization of avascular tissues such as skin grafts, probably owing to its stimulating effect on angiogenesis.
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Affiliation(s)
- Emre Vural
- Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, 4301 W Markham, Slot 543, Little Rock, AR 72205, USA.
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Lee SG, Yang JW, Park SG, Yang YI. Effect of stem cells and fibrin concentration on the vascularization of the Medpor orbital implant. Clin Exp Ophthalmol 2010; 38:885-91. [PMID: 20572821 DOI: 10.1111/j.1442-9071.2010.02355.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND To determine the effect of adipose-derived adult stem cells (ADASCs) and optimal concentration of fibrin on fibrovascular ingrowth into porous polyethylene orbital implants (Medpor). METHODS Medpor sheet treated with O.25% fibrin only and ADASCs in mixtures containing fibrin (0.25%, 0.5% or 1.25%) were applied to a Medpor sheet and implanted in the back of each of 20 athymic nude mice. After 10 days, implants were removed and observed for fibrovascularization and stability. Haemoglobin, collagen and cellular DNA content were determined in quantitative assays. RESULTS Haemoglobin, collagen and cellular DNA levels were significantly higher in ADASC group than in the cell-free implant (0.25% fibrin only) group (P < 0.01). The level of haemoglobin and collagen content was significantly higher in the ADASC + 0.5% fibrin group among the ADASC and fibrin mixtures (P < 0.01). CONCLUSION ADASCs significantly improved fibrovascularization on Medpor compared with implants alone. Fibrin, used together with ADASCs to potentiate fibrovascularization, was most effective at concentrations of 0.5%.
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Affiliation(s)
- Sul-Gee Lee
- Department of Ophthalmology, Inje University, Busan, Republic of Korea
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8
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Liu PY, Tong W, Liu K, Han SH, Wang XT, Badiavas E, Rieger-Christ K, Summerhayes I. Liposome-mediated transfer of vascular endothelial growth factor cDNA augments survival of random-pattern skin flaps in the rat. Wound Repair Regen 2009. [DOI: 10.1111/j.1067-1927.2004.012114.x-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Application of AAV2-mediated bFGF gene therapy on survival of ischemic flaps: effects of timing of gene transfer. Ann Plast Surg 2009; 62:87-91. [PMID: 19131728 DOI: 10.1097/sap.0b013e31817439fe] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Necrosis of surgically transferred flaps is a major problem in reconstructive surgery. We investigated efficacy of a new vector system-adeno-associated viral 2 (AAV2)-mediated bFGF gene transfer to enhance survival of the ischemic flap. Thirty-eight Sprague-Dawley rats were divided into 3 gene therapy groups and 1 nontreated control of 9 or 10 each. 7.5 x 10(10) AAV2-bFGF viral particles were injected to the dorsum of each of the 29 rats; these rats were divided into 3 groups according to the timing of flap elevation. At the time of surgery, 1 week, and 2 weeks after surgery, flaps of 3 x 7 cm were raised. One week after surgery, flap viability was measured. Vascularization and immunohistochemical staining of the bFGF were evaluated of histologic sections. Flap viability was significantly improved by the AAV2-bFGF gene therapy at the time of surgery, and the flaps with the greatest survival area were found in the rats injected with AAV2-bFGF, 2 weeks before surgery. However, flap viability was significantly decreased by the gene therapy 1 week before surgery. Histologically, vascularity was increased in the groups with AAV2-bFGF injection and immunohistochemical staining showed greatly enhanced bFGF expression by gene transfer. The novel approach of AAV2-bFGF gene therapy shows encouraging manifestations in improving survival of flaps when the flaps are prefabricated during or 2 weeks before surgery.
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Yang JW, Lee HY, Park SG, Yang YI. The Role of Endothelial Progenital Cells and Fibrin on Vascularization and Stability in Orbital Implant. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2008. [DOI: 10.3341/jkos.2007.49.7.1135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jae Wook Yang
- Department of Ophthalmology, College of Medicine, Inje University, Pusan, Korea
| | - Ho Young Lee
- Department of Ophthalmology, College of Medicine, Inje University, Pusan, Korea
| | - Sae Gwang Park
- Department of Microbiology, College of Medicine, Inje University, Pusan, Korea
| | - Young Il Yang
- Department of Pathology, College of Medicine, Inje University, Pusan, Korea
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11
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Chen W, Zhang F, Chen MB, Lineaweaver WC. Expression of Vascular Endothelial Growth Factor Receptor-2 in the Muscle Flap with Ischemic Injury in Rats. J Surg Res 2007; 140:45-9. [PMID: 17418870 DOI: 10.1016/j.jss.2006.10.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 10/09/2006] [Accepted: 10/30/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Ischemia of muscle flaps is a significant problem in reconstructive surgery. Administration of either recombinant vascular endothelium growth factor (VEGF) protein or gene transfers has been conducted to improve the survival of ischemic tissue. These biophysiological functions of VEGF are mediated through its receptor. In this study the changes of expression in VEGF receptor mRNA in muscle flaps with acute ischemia were examined in a rat gracilis muscle flap model. MATERIALS AND METHODS Twenty-four Sprague Dawley rats were used. The ischemia of the flap was induced by clamping its vascular pedicle. At 3-, 6-, and 18-h intervals, the flaps were biopsied for histology and examination of VEGFR-2 mRNA gene expression. The muscle flap without ischemia was used as the control. RESULTS The results showed that the VEGFR-2 mRNA level was significantly increased 3 h after ischemia was induced and then attenuated to the baseline at 6 and 18 h ischemia. CONCLUSIONS This study delineated the changes in expression of VEGFR-2 receptor in muscle flap in several postischemic intervals and provided a timeframe for the clinical application of VEGF.
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Affiliation(s)
- Weijia Chen
- Division of Plastic Surgery, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
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12
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Antonini A, Zacchigna S, Papa G, Novati F, Pascone M, Giacca M. Improved survival of rat ischemic cutaneous and musculocutaneous flaps after VEGF gene transfer. Microsurgery 2007; 27:439-45. [PMID: 17596844 DOI: 10.1002/micr.20378] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
When harvesting microsurgical flaps, the main goals are to obtain as much tissue as possible based on a single vascular pedicle and a reliable vascularization of the entire flap. These aims being in contrast to each other, microsurgeons have been looking for an effective way to enhance skin and muscle perfusion in order to avoid partial flap loss in reconstructive surgery. In this study we demonstrate the efficacy of VEGF 165 delivered by an Adeno-Associated Virus (AAV) vector in two widely recognized rat flap models. In the rectus abdominis myocutaneous flap, intramuscular injection of AAV-VEGF reduced flap necrosis by 50%, while cutaneous delivery of the same amount of vector put down the epigastric flap's ischemia by >40%. Histological evidence of neoangiogenesis (enhanced presence of CD31-positive capillaries and alpha-Smooth Muscle Actin-positive arteriolae) confirmed the therapeutic effect of AAV-VEGF on flap perfusion.
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Affiliation(s)
- Andrea Antonini
- Plastic Surgery Unit, Faculty of Medicine and Surgery, University of Trieste, Italy.
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13
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Liu PY, Liu K, Wang XT, Badiavas E, Rieger-Christ KM, Tang JB, Summerhayes IC. Efficacy of Combination Gene Therapy with Multiple Growth Factor cDNAs to Enhance Skin Flap Survival in a Rat Model. DNA Cell Biol 2005; 24:751-7. [PMID: 16274295 DOI: 10.1089/dna.2005.24.751] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The objective of this study was to investigate the efficacy of combination gene therapy with multiple angiogenic growth factor cDNAs to enhance survival of ischemic skin flaps in a rat model. Sixty Sprague-Dawley rats were divided into six groups. Varying combinations of VEGF165, PDGF-B, and bFGF-plasmids were injected to prefabricate the flaps. Random skin flaps were raised on the dorsal aspect of rats following prefabrication with growth factor cDNAs. Flap viability was determined by measurement of percentage area of survival. The efficacy of gene therapy was evaluated by flap survival and neovascularization of representative histologic sections stained immunohistologically. The VEGF165 plus bFGF cDNAs enhanced the viability of the flap and neovascularization most effectively; the flap survival area was 64.3 +/- 8.7% after transfer of these two growth factor genes. Addition of PDGF-B cDNA is deleterious to the effects of combined VEGF165 and bFGF, leading to a significant decrease in flap viability (44.9 +/- 2.7%). Viability of the flaps with combined VEGF165 and bFGF cDNA transfer was significantly greater than that of the flaps with VEGF165 transfer alone (57.6 +/- 5.2%) or sham plasmid control (52.3 +/- 5.0%). Combined transfer of VEGF165 and bFGF cDNA is the most effective combination of multiple growth factor genes to improve flap viability in this model. Simultaneous transfer of three growth factor genes (VEGF165, PDGF-B, and bFGF) is deleterious to flap survival, at least for the ratio of lipofectin:transgene employed.
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Affiliation(s)
- Paul Y Liu
- Department of Surgery, Roger Williams Medical Center, Providence, Rhode Island 02908, USA.
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14
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Conrad C, Huss R. Adult stem cell lines in regenerative medicine and reconstructive surgery. J Surg Res 2005; 124:201-8. [PMID: 15820249 DOI: 10.1016/j.jss.2004.09.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Indexed: 12/23/2022]
Abstract
In recent years, there has been a tremendous increase in the understanding of stem cell biology. The potential clinical applications lead to an extended interest in the use of stem cells in many medical disciplines. Multipotent adult stem cells seem to be almost comparable to embryonic stem cells with respect to their ability to differentiate into various tissues in vitro and in vivo, a function that has been termed "stem cell plasticity". In vivo experiments in rodents have shown that adult stem cells participate in tissue- and organ regeneration in almost all lesions. Although stem cell populations isolated from the bone marrow are usually a heterogeneous mix of different subpopulations, cloned adult stem cell lines from any source also show a broad spectrum of differentiation potential, e.g., osteogenesis, myogenesis, neurogenesis, or angiogenesis in wound healing. Angiogenesis in particular is a subject in tissue regeneration with tremendous implication in reconstructive surgery. This comprehensive plasticity makes it possible to use stem cell lines for biomedical research, tissue engineering, regenerative surgery, and organ repair. Adult stem cell lines are molecularly well defined with respect to transcription factors, active signal transduction pathways, and expression of receptors/ligand pairs. We performed experiments with adult stem cell lines, which are not subject to stem cell heterogeneity. Results obtained with stem cell lines can reliably be ascribed to the stem cell population under scrutiny. Adult stem cell lines can be obtained with the necessary quality and quantity also to study many effects of human stem cells in vitro and in vivo. In this paper, we summarize some of the tremendous therapeutic implications of adult stem cell lines in surgery and surgical research.
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Affiliation(s)
- Claudius Conrad
- Department of Surgery, University of Munich, Munich, Germany
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15
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Katsube K, Bishop AT, Simari RD, Ylä-Herttuala S, Friedrich PF. Vascular endothelial growth factor (VEGF) gene transfer enhances surgical revascularization of necrotic bone. J Orthop Res 2005; 23:469-74. [PMID: 15734264 DOI: 10.1016/j.orthres.2004.08.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Avascular necrosis of bone is a relatively common clinical condition caused by inflammatory conditions, steroid or other drug use, and trauma that affect many different sites in man. Revascularization of the necrotic bone is slow to occur, often resulting in bone resorption and eventual collapse of the involved bone. Rapid revascularization and subsequent bone remodeling may lead to improved outcomes. Surgical revascularization with arterovenous bundles (AV bundles) or vascularized bone grafts results in neoangiogenesis and bone remodeling. Gene transfer of an angiogenic factor to the vessel wall may be an additional strategy to further accelerate this process. In this study, we examined the effectiveness of vascular endothelial growth factor (VEGF) gene transfer to augment surgical revascularization of necrotic bone. An adenoviral vector, either with the VEGF gene (VEGF-A) or identical virus without the cDNA VEGF insert (ADV-DeltaE1) was used to transduce endothelial cells in rabbit saphenous arteries. The artery was then placed with its venae comitantes as an AV bundle into necrotic iliac crest bone in vivo. Angiogenesis in the necrotic bone was quantified by bone blood flow measurement and assessment of vessel density following microangiography. The extent of neoangiogenesis was significantly greater in the VEGF group than the control group at 1 week postoperatively.
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Affiliation(s)
- Kosuke Katsube
- Department of Orthopedic Surgery, Microvascular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
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16
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Erdmann D, Pippen AM, Moquin KJ, Sweis R, Niklason LE, Levin LS, Olbrich KC, Klitzman B. Immunohistochemical Identification of Vascular Endothelial Growth Factor in Pig Latissimus Dorsi Musculocutaneous Flaps Following Ischemia-Reperfusion Injury. Ann Plast Surg 2004; 53:398-403. [PMID: 15385779 DOI: 10.1097/01.sap.0000125503.69220.69] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Vascular Endothelial Growth Factor (VEGF), a potent angiogenic, mitogenic and vascular permeability enhancing protein, appears to improve survival of ischemic flaps independent of its route of administration. The purpose of this study was to examine VEGF protein expression in biopsies of surgical flaps with immunohistochemical techniques. In 6 male Yorkshire-type pigs, 10 cm x 15 cm Latissimus dorsi musculocutaneous flaps were elevated bilaterally. Flap zones I, II, and III were established according to their distance from the vascular pedicle. After isolation of the thoracodorsal artery and vein, one flap was randomly assigned to ischemia by temporary occlusion of the vascular pedicle. Ischemia (4 hours) was followed by 2 hours of reperfusion (ischemia group, n = 6). The contralateral (nonischemic) flap served as a control (control group, n =6). Skin and muscle biopsies of flaps were taken at the end of the protocol for immunohistochemical staining using a VEGF antihuman monoclonal antibody. Epidermis of flap skin did not demonstrate VEGF-positive staining, but the dermis and subcutaneous tissue did. Muscle components of biopsies demonstrated staining of interfascicular septa and staining of myocytes. A semi-quantitative scoring system with a scale of 0 to 3 was used for grading of immunohistochemical staining. In skin, areas adjacent to the flap showed an overall mean VEGF staining score of 0.7. All zones of ischemic flaps showed increased mean immunohistochemical staining for VEGF (scores = 1.2, 1.6, and 1.4 in zones I, II, and III, respectively). In muscle, however, only zone I showed increased VEGF immunohistochemical staining from 0.7 in adjacent areas to 1.7 in ischemic flaps. The results indicate only moderate endogenous up-regulation of VEGF in flaps, supporting the utilization of exogenous VEGF as an adjunct in microsurgical therapy.
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Affiliation(s)
- Detlev Erdmann
- Kenan Plastic Surgery Research Laboratories, Division of Plastic, Reconstructive, Maxillofacial and Oral Surgery, Duke University Medical Center, Durham, NC, USA.
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17
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Abstract
Growth factors are members of a large functional group of polypeptide regulatory molecules that influence the biological activities of responsive cells. In the last decade, the use of a variety of growth factors as therapeutic agents to improve wound healing and the viability of ischemic skin flaps has aroused considerable interest. Here, we review the literature concerning the regulation of growth factors in a flap, the role of angiogenesis in flap survival, the effect of growth factors on the metabolism of a flap, and angiogenesis in flap prefabrication and maturation. The potential application of growth factors in gene therapies is also reviewed.
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Affiliation(s)
- Feng Zhang
- Division of Plastic Surgery, University of Mississippi Medical Center, Jackson, MS 39216, USA
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18
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Ward WK, Quinn MJ, Wood MD, Tiekotter KL, Pidikiti S, Gallagher JA. Vascularizing the tissue surrounding a model biosensor: how localized is the effect of a subcutaneous infusion of vascular endothelial growth factor (VEGF)? Biosens Bioelectron 2004; 19:155-63. [PMID: 14611750 DOI: 10.1016/s0956-5663(03)00180-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Implantable continuous biosensors would improve disease management but long term function of such devices have been limited by a hypovascular foreign body capsule that inhibits influx of analytes. To assess whether capsule vascularity could be increased, we studied the histologic effects of a 28-day continuous infusion of vascular endothelial growth factor (VEGF) (0.45 microg/day) vs. saline from the surface of a model disk biosensor that was implanted subcutaneously in rats. At day 40, tissue was obtained at varying distances from the infusion port and capsular microvessels were counted using two histologic techniques. VEGF treatment led to a marked increase in capillary density. In tissue located 1 mm away from the infusion site, capillary density in VEGF-treated animals was 200-300% higher than in saline controls. Tissue located 13 mm away, but not 25 mm away, also demonstrated neovascularization. Serum obtained from a distant vein during the infusion did not show an elevated concentration of VEGF. These data demonstrate that a subcutaneous infusion of VEGF creates localized neovascularization of the foreign body capsule and suggest that systemic effects of VEGF are avoidable. Vascularization of a foreign body capsule surrounding a subcutaneous biosensor might well extend its useful life.
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Affiliation(s)
- W Kenneth Ward
- Legacy Health System, Legacy Clinical Research and Technology Center, 1225 NE 2nd Avenue, Portland, OR 97232, USA.
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19
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Abstract
Growth factors are members of a large functional group of polypeptide regulatory molecules that exert a powerful influence on all phases of wound healing and repair through interactions with specific cell surface receptors. The use of growth factors to improve wound healing and the viability of ischemic skin flaps has been well-documented throughout the last decade. In this article, we review the literature concerning the use gene therapy in flap survival, including the various methods employed to transplant plasmids or viruses capable of coding and producing growth factors in ischemic tissue.
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Affiliation(s)
- William Waller
- Division of Plastic Surgery, University of Mississippi Medical Center, Jackson, MS 39216, USA
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20
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Park S, Tepper OM, Galiano RD, Capla JM, Baharestani S, Kleinman ME, Pelo CR, Levine JP, Gurtner GC. Selective recruitment of endothelial progenitor cells to ischemic tissues with increased neovascularization. Plast Reconstr Surg 2004; 113:284-93. [PMID: 14707648 DOI: 10.1097/01.prs.0000091169.51035.a5] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Tissue ischemia remains a common problem in plastic surgery and one for which proangiogenic approaches have been investigated. Given the recent discovery of circulating endothelial stem or progenitor cells that are able to form new blood vessels, the authors sought to determine whether these cells might selectively traffic to regions of tissue ischemia and induce neovascularization. Endothelial progenitor cells were isolated from the peripheral blood of healthy human volunteers and expanded ex vivo for 7 days. Elevation of a cranially based random-pattern skin flap was performed in nude mice, after which they were injected with fluorescent-labeled endothelial progenitor cells (5 x 10(5); n = 15), fluorescent-labeled human microvascular endothelial cells (5 x 10(5); n = 15), or media alone (n = 15). Histologic examination demonstrated that endothelial progenitor cells were recruited to ischemic tissue and first appeared by postoperative day 3. Subsequently, endothelial progenitor cell numbers increased exponentially over time for the remainder of the study [0 cells/mm2 at day 0 (n = 3), 9.6 +/- 0.9 cells/mm2 at day 3 (n = 3), 24.6 +/- 1.5 cells/mm2 at day 7 (n = 3), and 196.3 +/- 9.6 cells/mm2 at day 14 (n = 9)]. At all time points, endothelial progenitor cells localized preferentially to ischemic tissue and healing wound edges, and were not observed in normal, uninjured tissues. Endothelial progenitor cell transplantation led to a statistically significant increase in vascular density in ischemic tissues by postoperative day 14 [28.7 +/- 1.2 in the endothelial progenitor cell group (n = 9) versus 18 +/- 1.1 in the control media group (n = 9) and 17.7 +/- 1.0 in the human microvascular endothelial cell group (n = 9; p < 0.01)]. Endothelial progenitor cell transplantation also showed trends toward increased flap survival [171.2 +/- 18 mm2 in the endothelial progenitor cell group (n = 12) versus 134.2 +/- 10 mm2 in the media group (n = 12) and 145.0 +/- 13 mm2 in the human microvascular endothelial cell group (n = 12)], but this did not reach statistical significance. These findings indicate that local tissue ischemia is a potent stimulus for the recruitment of circulating endothelial progenitor cells. Systemic delivery of endothelial progenitor cells increased neovascularization and suggests that autologous endothelial progenitor cell transplantation may have a role in the salvage of ischemic tissue.
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Affiliation(s)
- Sanghoon Park
- Laboratory of Microvascular Research and Vascular Tissue Engineering, Institute of Reconstructive Plastic Surgery, New York University, NY, USA
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21
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Suzuki O, Bishop AT, Sunagawa T, Katsube K, Friedrich PF. VEGF-promoted surgical angiogenesis in necrotic bone. Microsurgery 2004; 24:85-91. [PMID: 14748033 DOI: 10.1002/micr.10190] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The ability of vascular endothelial growth factor (VEGF) to accelerate neoangiogenesis from implanted arterovenous (AV) bundles in necrotic bone was evaluated. A saphenous AV bundle was placed in a necrotic segment of rabbit ilium. In group II, VEGF (100 ng/h x 3 days) was administered by continuous infusion. Bone blood flow was measured with radioactive-labeled microspheres, and capillary density was determined by microangiography combined with Spälteholtz bone clearing at 1, 2, and 4 weeks. Neovascularization was observed along the implanted vascular bundle in both groups. One week after surgery, bone blood flow and vessel area were significantly higher in VEGF-treated animals (P < 0.05). No significant difference was observed at later times. Direct VEGF administration increased surgical angiogenesis and improved blood flow and neovascularization in necrotic bone 1 week after AV bundle implantation. Thereafter, a robust angiogenic response from the AV bundle was seen in both groups.
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Affiliation(s)
- Osami Suzuki
- Department of Orthopedic Surgery, Microvascular Research Laboratory, Mayo Clinic, Rochester, MN, USA
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22
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Abstract
Apoptosis, or programmed cell death, is a phenomenon that is integral to development and cellular homeostasis. In the last decade, many of the essential molecules and pathways that control this phenomenon have been elucidated. Because apoptosis is involved in almost all physiologic and pathologic processes, the understanding of its regulation has significant clinical ramifications. This article reviews the basic understanding of programmed cell death in terms of the effector molecules and pathways. Areas of interest to plastic surgeons are reviewed as they pertain to apoptosis. These areas include allotransplantation, craniofacial and limb development, flap survival, wound healing, stem cell science, and physiologic aging. These topics have not yet been studied extensively in the context of cell death. In this review article, other related and more comprehensively studied scientific areas are used to extrapolate their relevance to apoptosis. Apoptosis is an increasingly better understood process. With the knowledge of how programmed cell death is controlled, combined with the improved ability to effectively perform genetic manipulation and to design specific chemical approaches, apoptosis is gaining clinical relevance. In the next few years, practical clinical breakthroughs will help the medical community to understand the phenomenon of apoptosis and how it relates to the needs of patients.
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Affiliation(s)
- Brian R Gastman
- Department of Otolaryngology, University of Pittsburgh Shool of Medicine, Pa, USA.
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23
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Erdmann D, Sweis R, Wong MS, Niklason LE, du Laney TV, Levin LS, Klitzman B, Olbrich KC. Vascular endothelial growth factor expression in pig latissimus dorsi myocutaneous flaps after ischemia reperfusion injury. Plast Reconstr Surg 2003; 111:775-80. [PMID: 12560698 DOI: 10.1097/01.prs.0000041534.99907.75] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Exogenous administration of vascular endothelial growth factor (VEGF) improves long-term viability of myocutaneous flaps. However, endogenous expression of this substance in flaps following ischemia-reperfusion injury has not been reported previously. Endogenous production of VEGF was measured in myocutaneous pig latissimus dorsi flaps after ischemia-reperfusion injury. Latissimus dorsi myocutaneous flaps (15 x 10 cm) were simultaneously elevated bilaterally in six Yorkshire-type male pigs (25 kg). Before elevation, three flap zones (5 x 10 cm) were marked according to their distance from the vascular pedicle. After isolation of the vascular pedicle, ischemia-reperfusion injury was induced in one flap by occlusion of the thoracodorsal artery and vein for 4 hours, followed by 2 hours of reperfusion. The contralateral flap served as a control. Perfusion in each zone was monitored by laser Doppler flowmetry at baseline, during ischemia, and during reperfusion. At the end of the protocol, skin and muscle biopsies of each flap zone and adjacent tissues were obtained for later determination of VEGF protein levels. VEGF concentrations were quantified using the Quantikine human VEGF immunoassay. Skin perfusion was similar among all flap zones before surgery. Flow fell in all flaps immediately after flap elevation. After 4 hours of ischemia, blood flow in the ischemic flaps was significantly decreased (p < 0.05) compared with nonischemic control flaps. After 2 hours of reperfusion, flow in ischemic flap skin recovered to levels similar to those in control flaps. VEGF protein concentrations in muscle tissue exceeded concentrations in skin and decreased from zones 2 to 3 in control and ischemic flaps. No significant differences in VEGF concentrations between ischemic and control muscle zones were observed. However, the concentration of VEGF in all muscle zones was significantly higher (p < 0.05) than muscle adjacent to the flap. Concentrations in skin zones 1 and 2 were significantly higher (p < 0.05) in ischemic flaps than in control flaps, but levels in zone 3 (most ischemic flaps) showed no significant difference.
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Affiliation(s)
- Detlev Erdmann
- Division of Plastic, Reconstructive, Maxillofacial, and Oral Surgery, Duke University Medical Center and Duke University, Durham, NC 27710, USA
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24
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Gurunluoglu R, Ozer K, Skugor B, Lubiatowski P, Carnevale K, Siemionow M. Effect of transfection time on the survival of epigastric skin flaps pretreated with adenovirus encoding the VEGF gene. Ann Plast Surg 2002; 49:161-9. [PMID: 12187344 DOI: 10.1097/00000637-200208000-00009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
An experimental study was conducted to investigate the effect of time of adenovirus-mediated vascular endothelial growth factor (VEGF) gene therapy on the viability of epigastric skin flaps. Eighty-four male Sprague-Dawley rats were used. Skin flaps measuring 8 x 8 cm were marked on the ventral abdominal wall. The upper border of the flap was 1 cm above the costal margin, and the lower border was at the pubis and the inguinal fold. The lateral borders of the flap corresponded to the location of the distinct conversion of the thin ventral skin to the thick dorsal skin. Seven sites in the predicted area of necrosis on the outlined skin flaps were chosen for subdermal injections. All injections were administered by an individual who was blinded to the different treatment groups. The rats received either saline (control group I, N = 28) or adenovirus encoding green fluorescent protein (Ad-GFP; group II, N = 28) or Ad-VEGF (group III, N = 28). The epigastric island skin flaps based solely on the right inferior epigastric vessels were elevated either on the same day of injection (day 0 = 12 hours after transfection, N = 7) or on day 3 (N = 7), day 7 (N = 7), or day 14 (N = 7) after subdermal gene therapy. Flaps were sutured back to their native configuration. Flap viability was evaluated on day 7 after surgery. Sections of the flaps were examined histologically after undergoing hematoxylin-eosin staining. There was a significant reduction in mean percentage of necrotic flap area by 56%, 67%, 70%, and 54% in flaps transfected with Ad-VEGF, 12 hours, 3 days, 7 days, and 14 days before flap elevation, respectively ( < 0.05). There was no evidence that the mean percentage of skin necrosis in the Ad-GFP group was different than in the control group ( = 0.26). There was evidence of mild inflammation in flaps pretreated with Ad-GFP and Ad-VEGF compared with the control group. The authors demonstrated that adenovirus-mediated gene therapy of the abdominal skin after subdermal injections was technically feasible. This was demonstrated by the visualization of GFP expression in control experiments using a fluorescence microscope. In this study, adenovirus-mediated VEGF gene therapy promoted epigastric flap survival, which was not related to the time of transfection. These findings raise the possibility that pretreatment with VEGF gene therapy using an adenovirus vector may be applicable in patients at risk for plastic surgery.
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Affiliation(s)
- Raffi Gurunluoglu
- Department of Plastic and Reconstructive Surgery, The Cleveland Clinic Foundation, OH 44195, USA
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25
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Lubiatowski P, Gurunluoglu R, Goldman CK, Skugor B, Carnevale K, Siemionow M. Gene therapy by adenovirus-mediated vascular endothelial growth factor and angiopoietin-1 promotes perfusion of muscle flaps. Plast Reconstr Surg 2002; 110:149-59. [PMID: 12087246 DOI: 10.1097/00006534-200207000-00026] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
An experimental study was conducted to investigate the potential use of intravascular gene therapy with adenovirus-mediated (Ad) vascular endothelial growth factor (VEGF) or angiopoietin-1 (Ang-1) for the enhancement of muscle flap perfusion and to evaluate the effect of therapy on microcirculatory hemodynamics and microvascular permeability in vivo by using a cremaster muscle flap model in the rat. The cremaster tube flap was left intact after isolation of the pudo-epigastric pedicle. A total of 90 male Sprague-Dawley rats were divided into five groups of 18 each, according to the type of intraarterial treatment. Control flaps received phosphate-buffered saline. Group 2 (the control gene encoding green fluorescent protein, Ad-GFP) served as the adenovirus control. In Groups 3, 4, and 5, flaps were pretreated with Ad-VEGF, Ad-Ang-1, and Ad-Ang-1 + Ad-VEGF, respectively. Flaps were preserved in a subcutaneous pocket in the hindlimb for evaluation of functional capillary density and microvascular permeability indices at 3, 7, and 14 days by intravital microscopy system. At day 7 and 14, Ad-VEGF, Ad-Ang-1, and combined treatment groups showed significantly higher numbers of capillary densities when compared with control and Ad-GFP groups (p < 0.05). At day 14, Ad-VEGF was the superior treatment group compared with Ad-Ang-1 and Ad-VEGF + Ad-Ang-1 (p < 0.05). Overall, there was a linear increase in the number of functional capillaries in all treatment groups (p < 0.05). At day 3 after Ad-Ang-1 therapy, a significantly lower permeability index was found when compared with Ad-VEGF + Ad-Ang-1 and Ad-VEGF alone treatment (p < 0.05). At day 7, the Ad-VEGF group had the highest score of permeability index compared with control, combined, and Ad-Ang-1 groups (p < 0.05). Histologic evaluation of muscle flaps demonstrated mild focal inflammation. There was evidence of mild vasculitis in all flaps except control muscles. Intravascular angiogenic therapy with Ad-VEGF or Ad-Ang-1 was technically feasible, as demonstrated by expression of the control gene, GFP, along the vascular tree. All treatment groups increased perfusion of the muscle flap over a period of 14 days, indicating a long-lasting effect of gene therapy. Ang-1 alone or in combination with VEGF was as effective as VEGF alone in augmenting muscle perfusion with more stable vessels 1 week after gene therapy.
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Affiliation(s)
- Przemyslaw Lubiatowski
- Department of Plastic and Reconstructive Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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26
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Lubiatowski P, Goldman CK, Gurunluoglu R, Carnevale K, Siemionow M. Enhancement of epigastric skin flap survival by adenovirus-mediated VEGF gene therapy. Plast Reconstr Surg 2002; 109:1986-93. [PMID: 11994603 DOI: 10.1097/00006534-200205000-00031] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A novel approach to treat ischemic tissues by using gene therapy has recently been introduced on the basis of the angiogenic potential of certain growth factors. The authors investigated the effect of adenovirus-mediated gene therapy with vascular endothelial growth factor (VEGF) delivered into the subdermal space to treat compromised skin flaps. For this purpose, the epigastric skin flap model in rats, based solely on the right inferior epigastric vessels, was used. Thirty male Sprague-Dawley rats were divided into five groups of six rats each. Viral transfection with 108 plaque-forming units was performed 2 days before the epigastric flap elevation. Rats received subdermal injections of adenovirus encoding VEGF (Ad-VEGF) or green fluorescent protein (Ad-GFP) as treatment control. Another set of animals (n = 6) received no injections and were designated as control. To determine whether site of injection had an impact on flap viability, injections were given into the predicted local ischemic area (Ad-VEGF local, n = 6; Ad-GFP local, n = 6) and into the midline of the flap (Ad-VEGF midline, n = 6; Ad-GFP midline, n = 6). A flap measuring 8 x 8 cm was outlined on the abdominal skin extending from the xiphoid process proximally and the pubic region distally, to the anterior axillary lines bilaterally. Then, the epigastric flap was elevated as an island on the right inferior epigastric vessels and sutured back to its bed. Flap viability was evaluated at 7 and 14 days after the first operation. The epigastric flaps were scanned to the computer and areas of hypoxic and/or necrotic zones relative to total flap surface area were measured and expressed as percentages by using Image Pro Plus software. Specimens were taken for histologic evaluation at day 14 before the animals were killed. Combined area of necrotic and hypoxic zones as well as necrotic zone were decreased to 9.7 +/- 1.4 percent and 1.4 +/- 0.9 percent in Ad-VEGF local, and 11.8 +/- 1.9 percent and 3.5 +/- 1.64 percent in Ad-VEGF midline compared with the control and Ad-GFP treatment groups (control, 23 +/- 3.6 percent and 20.1 +/- 3.3 percent; Ad-GFP local, 24.8 +/- 4.8 percent and 16.2 +/- 5.9 percent; and Ad-GFP midline, 23.4 +/- 6.9 percent and 19.5 +/- 7.7 percent; p < 0.05). Histologic evaluation by light microscopy failed to demonstrate any quantitative difference in vascularity of skin flaps between the treatment groups. In this study, the authors demonstrated that adenovirus-mediated gene therapy using VEGF enhanced epigastric skin flap survival, as confirmed by the significant reduction in combined area of necrotic and hypoxic zones of the flap. Compared with the control, both local and midline subdermal injections of Ad-VEGF showed improvement in overall flap survival by 57.9 and 48.7 percent, respectively. The results of this study raise the possibility of using adenovirus-mediated therapeutic angiogenesis for safer flap surgery in high-risk patients.
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Affiliation(s)
- Przemyslaw Lubiatowski
- Department of Plastic and Reconstructive Surgery, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
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27
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Neumeister MW, Song YH, Mowlavi A, Suchy H, Mathur A. Effects of liposome-mediated gene transfer of VEGF in ischemic rat gracilis muscle. Microsurgery 2001; 21:58-62. [PMID: 11288154 DOI: 10.1002/micr.1010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of the current study was to determine the effects of vascular endothelial growth factor (VEGF) on muscle flap survival and vascularity in a rat gracilis ischemia-reperfusion model. A total of 12 adult male Wistar rats were divided into two groups (n = 6). The experimental group received the plasmid encoding VEGF(165) cDNA plus lipofectamine (cationic liposome) injected directly to the gracilis muscle following 4 h of ischemia. The control group received lipofectamine only. The viability and vascularity of the flaps were evaluated after 7 days of reperfusion. The data demonstrated that the VEGF plasmid- and lipofectamine-treated muscle flaps had significantly greater total survival and capillary count 7 days after reperfusion compared with the flaps treated only with lipofectamine. These results indicate that VEGF exerts a protective effect on ischemic skeletal muscle flaps.
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Affiliation(s)
- M W Neumeister
- Institute for Plastic and Reconstructive Surgery, Southern Illinois University, School of Medicine, Springfield, Illinois 62794-9653, USA.
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